I don't have a central website, but I have collected quite a few resources over the short time that I've been managing PostageApp.
Whitelisting usually needs you to justify why your email should be let through into their email systems. Proactively applying for these will save you a bit of time, but will not save you from being blacklisted should your email behaviour not correspond with your application or if you are outright spamming people.
Feedback loops are for capturing spam and/or abuse complaints, in case users feel that they are receiving the email by mistake and/or being spammed by you.
You can check out both lists of major ISPs below.
You can also reply to the Return Path Certification which gives you whitelist on quite a few ISPs, which saves you a lot of time especially if you're sending a lot of bulk emails.
By no means an official list and probably not complete, but definitely a good start for you! We've gone through the process and I would love to make your life easier with the various resources we've found.
Anyone else reading this: if you have a resource that I haven't listed, definitely let me know via comments and I will add it to the list and give you credit. Thanks!